The present invention relates to a hand circular saw.
More particularly, it relates to a hand circular saw which has a saw blade swivellable on a support plate by means of a rocker about a swivel axis, and has a splitting wedge which is held on a splitting wedge carrier and by means of a guide device is swivellable about the axis of the saw blade.
From DE-C-28 54 369 (GB-B-800 625) a hand circular saw of this type is known. This saw is provided with a guide device for the splitting wedge and the casing of the hand circular saw. Together with the rocker carrying the saw blade the guide device forms a four-bar lever parallelogram. It holds the splitting wedge and the casing of the hand circular saw parallel to the support plate. If the rocker is swivelled, the splitting wedge and the casing of the hand circular saw follow it without changing the angular position.
Splitting wedges engage in the kerf formed in the workpiece during sawing. They maintain the distance between the halves of the workpiece, guide the rotating saw blade in a stable manner, and cover it. Sawing is thereby facilitated and the risk of injury is reduced. Splitting wedges are a legal requirement for circular saws. For reasons of working safety they must be permanently connected to the saw.
Plunge-cut or cross-cut saws are an exception; these can be lowered onto the workiece which is to be sawn. When the starting cut is made there is no room for the splitting wedge because no kerf has yet been made, so that before cutting starts the splitting wedge must be removed or be able to be uncoupled, through resilient suspension, from the swivelling movement of the rocker, as shown, for example, in the abovementioned patent specification.
A disadvantage of this guide device, which in itself is accurate and reliable, is constituted by the four joints, which are subject to wear. The joints are exposed to considerable shocks and the action of dust. In addition, the known guide device limits the swivelling angle of the hand circular saw and guidance becomes less accurate as the position of the rocker becomes steeper.